Virus Variants Threaten to Draw Out the Pandemic, Scientists Say

For weeks, mood swings have occurred in much of the United States. Coronovirus cases, hospitalizations and deaths have decreased from their height, and millions of people are being vaccinated every day. Restaurants, shops and schools have reopened. Some states, such as Texas and Florida, have dropped precautions altogether.

In measurable ways, Americans are winning the war against the coronaviruses. Powerful vaccines and a rapid rollout guarantee an ultimate return to all but normalcy – for backyard barbecues, summer camps and sleepovers.

But it is clear that the next few months will be painful. The so-called variants are spreading, carrying mutations that make the coronavirus more contagious and in some cases more lethal.

Even vaccines were authorized at the end of last year, with variants roaming the UK, South Africa and Brazil, illuminating a path to the end of the epidemic. New variants continue to pop-up California in a week New York And Oregon next. As they take root, these new versions of coronovirus threaten to end the epidemic.

At the moment, most vaccines appear to be effective against variants. But public health officials are deeply concerned that a recurrence of the virus in the future may be more resistant to the immune response, requiring Americans to regularly queue for booster shots or even new vaccines. is.

“We don’t have development,” said Devi Sridhar, professor of public health at the University of Edinburgh, Scotland. “This pathogen is always changing in a way that makes us harder to suppress.”

Health officials acknowledge the urgent need to track these new viruses as they crawl across the United States. Already, B.1.1.7, the highly contagious version that wallops Britain and wreaks havoc in continental Europe, is Growing rapidly In the United States.

Limited genetic testing has exceeded 12,500 cases, Many in Florida and Michigan. As of March 13, the variant accounted for 27 percent new Nationwide cases, down from just 1 percent in early February.

Biden administration has Mortgage pledged “down payment” of $ 200 million To ramp up surveillance, it is possible to perform an infusion to analyze 25,000 patient samples each week for variants of the virus. This is an ambitious goal: the country was sequencing just a few hundred samples each week in December, then increased to about 9,000 per week by 27 March.

Recently, the growth of B.1.1.7 was halted by falling rates of infection at all, leading Americans to a false sense of security and leading to restrictions on premature rest, researchers say .

“The best way to think of B.1.7 and other variants is to consider them as separate epidemics,” said Sebastian Funk, professor of infectious disease dynamics at the London School of Hygiene and Tropical Medicine. “We are sort of obscuring the scene by actually adding all those cases.”

Other variants identified in South Africa and Brazil, as well as some virus variants first seen in the United States, have slowed to spread. But they are also worrisome, as they contain a mutation that reduces the effectiveness of vaccines. This week, an outbreak of P.1 forced the closure of the Whistler Blackcomb ski resort in British Columbia, a version that crushed Brazil.

Scientists say that the world is stuck in a sprint between vaccines and variants and will eventually win. But because each infection allows the coronavirus to develop further, vaccination should proceed in the United States and elsewhere as soon as possible.

Infections are increasing again, driven to an indefinite degree by B.1.1.7 and other variants. Earlier this week, the director of the Centers for Disease Control and Prevention, Drs. Rochelle Wallensky told the Americans to continue practicing masking and social disturbances, adding that she felt a sense of “impending doom”.

“We have so much to look forward to – so much promise and potential where we are and so many reasons for hope,” she said. “But I’m scared right now.”

The coronovirus must have slowed down in order to change shape. Like all viruses, it will pick up mutations and evolve into thousands of variants, scientists said at the beginning of the epidemic. But it wouldn’t change significantly for the year – a stupid virus, some called it.

Pathogen defined those predictions. Viral immunologist at Washington University in St. Louis, Drs. “We expected the virus to change,” said Michael Diamond. “We didn’t anticipate very quickly how soon this was going to happen.”

A variant is only of concern if it is more contagious, causes more severe disease, or blunts the immune response. Identified variants in the UK, South Africa, Brazil and California all meet the criteria.

B.1.1.7, the first to come to wide attention, is about 60 percent more contagious And 67 percent More deadly According to the most recent estimates, the origin of the virus.

The variant is not different from the origin in how it spreads, but infected people Seems to carry more of the virus And for a long time, Katrina Lythgoe, an evolutionary biologist at the University of Oxford. “You’re more contagious for more days,” she said.

So contagious is B.1.1.7 that the UK was successful in reducing infections after almost three months of strict home orders, as well as an aggressive vaccination program. Nevertheless, cases fell much more slowly than during similar lockdowns in March and April.

In continental Europe, a wave of B.1.1.7 cases had been forming for months, mostly under a steady churn of infection that went unnoticed. The variant wave is now cresting.

Poland’s daily new cases rate has risen from mid-February to the end of February after forcing most public places to close. Germany has doubled by banning night ceremonies in Berlin.

In France, where B.1.1.7 is causing Three quarters of new infection, Some hospitals had to go to coronovirus patients Belgium To empty the beds. Roughly as many people have been dying every day since Kovid-19 in Europe, this was the time of the year before.

For too long, government officials ignored the threat. “Case Platius can hide the emergence of new variants,” said Carl Pearson, a research fellow at the London Case of Hygiene and Tropical Medicine. “And the higher they are on the plateau, the worse the problem.”

In the United States, the coronovirus infection began a rapid decline in January, soon prompting many state leaders to reopen businesses and ease restrictions. But scientists repeatedly Warned that the drop will not last. After nearly 55,000 cases per day and 1,500 deaths in mid-March, some states – notably Michigan – saw an uproar.

Since then, the national number has grown rapidly. until Saturday, The daily count was up to about 69,000, And the weekly average was 19 percent higher than the figure two weeks earlier.

Even when cases were falling, researchers questioned the notion of what the cause of the vaccination was. Millions of Americans are vaccinated every day, but still only 31 percent have received a single dose of a vaccine, and only 17 percent of the population have had complete protection, leaving a vast majority susceptible.

“The fact that we’re still in a situation where we don’t have enough vaccinated people,” said Christian Anderson, a virologist at Scripps Research, San Diego. “And if we, like Texas, say we’re done with Kovid-19, B.1.1.7 will come in and remind us that we’re not right. I have no doubt about that.”

The variant is particularly widespread in Florida, where the state lifted the ban and did not initially see an increase. Officials in other states cited it as justification for reopening. But now Florida’s infection rate is declining upward.

The variant has only been favored by scientists to call the season. Respiratory infections are typically rare in the spring in Florida, noted Sarah Kobe, an evolutionary biologist at the University of Chicago. The coronovirus infection was at its peak in Florida last year, as the heat drove people out of the home, and it may happen again.

“I still don’t think we’re out of the woods,” Dr. Kobe said, referring to the country at large. “If we don’t have another wave this spring, I’m really going to be, really worried about the fall.”

While most vaccines are effective against B.1.1.7, researchers are concerned about other variants that contain a mutation called E484K. (Scientists often refer to it appropriately, as “Eq.”)

This mutation has evolved independently in several variants worldwide, suggesting that it confers a powerful survival benefit to the virus.

In laboratory studies, Pfizer-bioentech And modern vaccines B.1.351 seem to be slightly less effective than the variants identified in South Africa. That variant contains eq mutations, which enable the virus to partially circumvent the body’s immune response. Vaccines made by Johnson and johnson, AstraZeneca And Novaxax Were also less powerful than those of B.1.351.

“I think for the next year or two, E484K will be the most concerning mutation”, said Jessie Bloom, evolutionary biologist at the Fred Hutchinson Cancer Research Center in Seattle.

The mutation slightly alters the so-called spike protein sitting on the surface of the coronovirus, making it just a little harder for the antibody to destroy the attacker.

The good news is that the virus feels that there are only a few survivors in its bag, and this makes it easier for scientists to find and block their defenses. “I’m feeling great about the fact that there aren’t a lot of options,” said Michelle Nusenzweig, an immunologist at Rockefeller University in New York.

Eq mutations appear to be the primary defense of the virus against the immune system. Researchers in South Africa recently reported that a new vaccine directed against B.1.351 should be discontinued, along with all other variants.

Pfizer, BioNotech, and Modern are already testing newly designed booster shots against B.1.351 that should work against any variant known to blunt the immune response.

Instead of a new vaccine against variants, however, it may be effective for Americans because a third dose of the Pfizer-BioNotech or Morden vaccine can be obtained for up to six months in a year, national head Dr. Anthony S. Fauci said. Institute of Allergy and Infectious Diseases.

He said that the antibody levels in each recipient would remain high, overwhelming any variant – a more practical strategy than creating a special vaccine for each new variant that would emerge.

“My only concern about chasing all the variants is that you’ll almost be playing Whac-A-Mole, you know, because they’ll keep coming up and coming up,” Dr. Fauci said.

In one form or another, new coronoviruses are here to stay, many scientists believe. Several variants may be prevalent in the country at the same time, as in the case of the common cold coronavir and influenza. Keeping them at bay may require an annual shot like a flu vaccine.

The best way to prevent the emergence of dangerous variants is to reduce cases now and land most parts of the world, not just the United States – as soon as possible. If significant pockets of the globe remain unprotected, the virus will continue to develop in dangerous new ways.

“This can be something we have to deal with for a long time,” said Epidemiologist Rosalind Agogo of the London School of Hygiene and Tropical Medicine.

Still, she said, “even if it changes again, which is very likely to happen, we are in a better, more robust position than we were a year ago to deal with it.”

Source link

Leave a Comment